I've got an xfusion Hilo sl.
It has been a massive massive pain in the arse. Been back 3 times.

Had a standard Hilo (sl was a free upgrade after my Hilo was trashed when it was back for warranty work) the seat lamp on the Hilo is useless, I couldn't get it done up tight enough to stop the saddle moving if I shifted my position. the clamp on the SL is much better

However it's working now and whilst it's working, it's quite good.
I think I've been a bit unlucky though. I'm looking at the RSP 27.2 dropper for my hard tail, anyone out there got one??

Me and the GF have run a small collection from the old speedballs through to the RSP and our go-to long termer is the Gravity Dropper (Turbo Multi flavour). Been ultra reliable and fully user rebuildable.

Had a second hand then bought a brand new Gravity Dropper- not he nicest looking item but reliable and easy to service- parts are easily found if needed.
I do like the look of the new Ks 272 but can't justify £330!

Specialized are also going to be releasing (at some point) an XC short travel Command post in 27.2 Only 50mm travel, but it might be good and seems light - bike shops expect it to be fairly cheap too (so I hear):

I have a T-Mars. It survived a week in Spain without any obvious issues. It's very cheap and I'm pretty happy with it. Only complaint is that the travel is a bit short at 100mm. If I was buying again, I'd want one with a bit more (or go to less hilly places or develop some actual skill).

I've got a 27.2 xfusion HiLo that I'm planning on putting on the classifieds when I get a moment. I've not had any problems with it, has remote, but has under seat lever bits with it if you aren't interested in the remote faff. If you're interested I can try and put an ad up with pics later.

I have had a cheap TMARS which was good until it snapped.
It was warrantied however and I sold the replacement. I weigh 93kg in my pants so that might have been an issue.

I'm now on my 2nd HiLo... the first one crept down and was replaced under warranty.

The replacement then decided to blow an air seal which meant that it didn't return once dropped without manual assistance.
This was fixed again under warranty (via Wiggle, took ages, required some chasing) and it has behaved on the 3 rides I have used it on since.

Would I buy another HiLo? Probably not. Would probably buy a Gravity Dropper, whilst not infinetly adjustable, the fact you can buy all the spares from CRC or direct and service the thing yourself counteracts that.

Was pondering a new frame and the choice is between one with 30.9 and one with a 27.2 and I think the GD is that well thought of I wouldn't let the 27.2 seatpost bother me...

my mates hi lo has been away for about 2 month on warranty with no sign of return..was fine until it gave up though…I've for a ks lev and had no probs except my own cack handed cable adjustment…apart from that sound